$-10t + 9u - 6v - 7 = -u - 10v + 5$ Solve for $t$.
Explanation: Combine constant terms on the right. $-10t + 9u - 6v - {7} = -u - 10v + {5}$ $-10t + 9u - 6v = -u - 10v + {12}$ Combine $v$ terms on the right. $-10t + 9u - {6v} = -u - {10v} + 12$ $-10t + 9u = -u - {4v} + 12$ Combine $u$ terms on the right. $-10t + {9u} = -{u} - 4v + 12$ $-10t = -{10u} - 4v + 12$ Isolate $t$ $-{10}t = -10u - 4v + 12$ $t = \dfrac{ -10u - 4v + 12 }{ -{10} }$ All of these terms are divisible by $2$ Divide by the common factor and swap signs so the denominator isn't negative. $t = \dfrac{ {5}u + {2}v - {6} }{ {5} }$